code: def test_item_iter(self):
      train_set = Dataset.from_uir(self.triplet_data)
  
      npt.assert_array_equal(
          np.arange(10).reshape(10, 1),
          [i for i in train_set.item_iter()],
      )
      self.assertRaises(
          AssertionError,
          npt.assert_array_equal,
          np.arange(10).reshape(10, 1),
          [i for i in train_set.item_iter(shuffle=True)],
      )
  
imports: import unittest
  import numpy
  import numpy.testing
  from cornac.data import BasketDataset, Dataset, SequentialDataset, Reader
label_desc: Use image node_id 9 for calling the TestDataset obj's underlying member method code with example usage: obj.test_item_iter() without return types